Solution : https://service.sap.com/sap/support/notes/355193 (SAP Service marketplace login required)
Key words : 
additional key words deletion flag, symptom wbs elements, wbs elements incorrectly, attached advance corrections, investment program positions, deletion flag, deletion indicator, program error, relevant projects, project exist
Related Notes : 
       
| 495726 | Overall plan incrct if WBS elemnt w/ deletn flag in project | 
| 441646 | Plan incorrect if WBS elements w/ deletion flag in project |